You want to nail a 1.6-kg board onto the wall of a barn. To position the board before nail...

You want to nail a 1.6-kg board onto the wall of a barn. To position the board before nailing, you push it against the wall with a horizontal force to keep it from sliding to the ground (Figure). (a) If the coefficient of static friction between the board and the wall is 0.79, what is the least force you can apply and still hold the board in place? (b) What happens to the force of sta tic friction if you push against the wall with a force greater than that found in part (a)?

FIGURE